package com.taimanetworks.utils;

import java.math.BigDecimal;

    /**
     * @author Mr.superbeyone
     * @project coordinate-convert-tools
     * @className LngLatConvertUtil
     * @description 地球坐标系(WGS - 84)转火星坐标系(GCJ)
     * @date 2020-04-14 10:21
     **/

    public class LngLatConvertUtil {

        private static final double PI = 3.14159265358979324;

        private static final double a = 6378245.0;

        private static final double EE = 0.00669342162296594323;


        /**
         * 地球坐标系(WGS-84)转火星坐标系(GCJ)
         *
         * @param wgLon 地球坐标系(WGS-84) 经度
         * @param wgLat 地球坐标系(WGS-84) 纬度
         * @return 火星坐标系(GCJ) 数组 0 经度；1 纬度
         */
        public static double[] transform(BigDecimal wgLon, BigDecimal wgLat) {
            return transform(wgLon.doubleValue(), wgLat.doubleValue());
        }

        /**
         * 地球坐标系(WGS-84)转火星坐标系(GCJ)
         *
         * @param wgLon 地球坐标系(WGS-84) 经度
         * @param wgLat 地球坐标系(WGS-84) 纬度
         * @return 火星坐标系(GCJ) 数组 0 经度；1 纬度
         */
        public static double[] transform(double wgLon, double wgLat) {
            double[] result = new double[2];

            if (outOfChina(wgLon, wgLat)) {
                result[0] = wgLon;
                result[1] = wgLat;
                return result;
            }
            double dLat = transformLat(wgLon - 105.0, wgLat - 35.0);
            double dLon = transformLon(wgLon - 105.0, wgLat - 35.0);
            double radLat = wgLat / 180.0 * PI;
            double magic = Math.sin(radLat);
            magic = 1 - EE * magic * magic;
            double sqrtMagic = Math.sqrt(magic);
            dLat = (dLat * 180.0) / ((a * (1 - EE)) / (magic * sqrtMagic) * PI);
            dLon = (dLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * PI);
            result[0] = wgLon + dLon;
            result[1] = wgLat + dLat;
            return result;
        }

        private static double transformLon(double x, double y) {
            double ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * Math.sqrt(Math.abs(x));
            ret += (20.0 * Math.sin(6.0 * x * PI) + 20.0 * Math.sin(2.0 * x * PI)) * 2.0 / 3.0;
            ret += (20.0 * Math.sin(x * PI) + 40.0 * Math.sin(x / 3.0 * PI)) * 2.0 / 3.0;
            ret += (150.0 * Math.sin(x / 12.0 * PI) + 300.0 * Math.sin(x / 30.0 * PI)) * 2.0 / 3.0;
            return ret;
        }

        private static double transformLat(double x, double y) {
            double ret = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2 * Math.sqrt(Math.abs(x));
            ret += (20.0 * Math.sin(6.0 * x * PI) + 20.0 * Math.sin(2.0 * x * PI)) * 2.0 / 3.0;
            ret += (20.0 * Math.sin(y * PI) + 40.0 * Math.sin(y / 3.0 * PI)) * 2.0 / 3.0;
            ret += (160.0 * Math.sin(y / 12.0 * PI) + 320 * Math.sin(y * PI / 30.0)) * 2.0 / 3.0;
            return ret;
        }

        /**
         * 在中国范围内
         *
         * @param lon 经度
         * @param lat 纬度
         * @return true 出中国
         */
        private static boolean outOfChina(double lon, double lat) {
            if ((lon < 72.004 || lon > 137.8347) && (lat < 0.8293 || lat > 55.8271)) {
                return true;
            } else {
                return false;
            }
        }

        public static void main(String[] args) {
            double[] result = LngLatConvertUtil.transform(112.455877,37.529124);
            System.out.println(result[0]+",  "+result[1]);
        }

    }
